A little known fact about the Sonus SBC range of appliances (previously NET UX appliances) is that they have a VGA header hidden behind the front bezel. If your appliance has an Application Solution Module (ASM) as part of it’s configuration, this is used to get console access to the ASM. This is useful in situations where you have lost connectivity to the ASM from the Sonus Web GUI (a rare occurrence, but it happens from time to time).
What constitutes lost connectivity to the ASM?
When a Sonus SBC appliance is deployed with the ASM module, the appliance is usually connected to the network with a single Ethernet link (this does not always apply, particularly for SBC 2000 gateways, but for the sake of the point I’m making, it’s connected with a single Ethernet lead). The SBC or gateway component of the appliance and the ASM both share a common physical Ethernet connection, but they are two separate logical devices in one: they each have their own unique IP address. For those that aren’t familiar with the ASM, it’s basically a windows server that runs on hardware within the SBC 1000/2000 chassis, and is used in Lync deployments to support the Survivable Branch Appliance (SBA) role in branch office deployments. You can read more about what an SBA is here.
The ASM communicates with the Sonus SBC 1000/2000 system using the SBC Communication Service. It’s a windows service that runs on the ASM, shown below:
From the Sonus Web GUI, you can view the version of the SBC Communications service, and as long as the ASM Board Status is displaying as Available, all is well in the world:
If however, your ASM display a board status of Unavailable, and no amount of rebooting brings it back, That’s when you’re in trouble. Here’s what issues with connectivity to the ASM looks like:
Usually when this occurs, and assuming there isn’t a hardware failure, you are left with one option: rebuild the ASM image using a USB recovery drive. At a high level, this process involves the following:
- Power down the appliance
- Insert specially prepared USB recovery drive
- Power up the appliance
- Twiddle your thumbs for around 40 minutes, remove the USB recovery drive and reboot
After this process is complete, the ASM board status should now display as available, and you can get on with rebuilding the ASM. The problem is, during that 40 minutes, you have no way of knowing what’s going on. Unless of course you have access to the console.
Accessing the console VGA port
UPDATE: The VGA adapter is only available to select Sonus partners. If this isn’t you, the recovery process is the same regardless of whether or not you have access to the console. Look out for a future blog from me in which I will go through the recovery process in more detail. The process is the same regardless of whether or not you have console access to the ASM.
To access the console, remove the bezel from the front of the appliance. There you will see a header near the ASM USB ports. To connect to this, you’ll need a VGA adapter lead, available from your Sonus distributor. You can also plug a USB keyboard/mouse into one of the ASM USB ports:
Here’s a sample screenshot, showing the kind of information that can be seen when the ASM is rebuilding, letting you know you’re not wasting your time:
I hope this has been useful.